TAMPA ­­— Even though Jeb Bush and Marco Rubio are looking and sounding serious as potential 2016 presidential candidates, their closest associates in Florida say they don’t believe the two will run against each other.

By the time of the 2016 Florida presidential primary at the latest, if both are still interested, one probably will defer to the other, those associates say. Before that, however, both are likely to test the waters and their fundraising and political support.

“I can’t imagine that in the Florida presidential primary, voters will have a choice between Jeb Bush and Marco Rubio,” said Brian Ballard, a Bush supporter and influential Tallahassee lobbyist.

In recent comments on the possibility of a Bush candidacy, Rubio has said he’ll make his decision without regard to who else is running. At the same time, high-level national Republican donors are urging urge Bush to enter the race.

“It’s what I would expect Sen. Rubio to say,” Ballard said.

Bush has acknowledged he’s considering a 2016 run. Since a decline in New Jersey Gov. Chris Christie’s ratings, blamed on the politically motivated shutdown of bridge traffic lanes, Republican campaign funders are widely reported viewing Bush as the candidate of the “mainstream,” business-oriented side of the GOP.

Rubio, meantime, has made staff moves recently that indicate a more serious attempt to develop his political base nationwide.

His long-time chief of staff, Cesar Conda, has moved to a position as adviser to Rubio’s political action committee, Reclaim America, moving up other staff members in his office to replace Conda.

Ever since appearances by Rubio and Bush at the 2012 Republican National Convention in Tampa, there’s been speculation about both as potential 2016 candidates.

It’s been an up-and-down ride for both, however, as they’ve taken political stances that could alienate the party’s political base — both, for example, favoring immigration reform including a path to citizenship for illegals, and Bush in favor of the Common Core national education standards.

Occasionally, both have been eclipsed by other potential candidates more acceptable to tea party-style Republicans, including Kentucky Sen. Rand Paul and Texas Sen. Ted Cruz.

Current polls show Bush near the top of the pack with Paul and former Arkansas Gov. Mike Huckabee in a broad field where no candidate reaches 15 percent. Rubio is in the center of that pack.

While Rubio has tried to hedge on his support for immigration reform, Bush shows no reluctance to take stances that could alienate the GOP’s tea party wing, making clear he won’t back off his views.

On the subject of illegal immigrants, he told an interviewer recently, “Yes they broke the law but it’s not a felony, it’s an act of love, an act of commitment to your family.” He prefaced those comments by saying he knew they could stir controversy among conservatives.

Bush, who has pronounced himself dissatisfied with the hyperpartisan state of politics including some elements of the Republican Party, added that he’ll run only if he can do so “joyfully”and “get beyond the harsh political rhetoric to a better place.”

Bush associates say that question, rather than a conflict with Rubio, is one of the two biggest considerations in whether he’ll run. The other is his family.

Though he and his close associates won’t discuss it publicly, his wife, Columba, is known to dislike the public spotlight.

“I think the way Jeb looks at the world is that who runs or doesn’t run isn’t part of what he’ll factor in,” said state Sen. John Thrasher, a close Bush associate. “He looks at it in terms of what’s best for him and his family — can he run a positive, optimistic race and is it in the best interest of his family.”

Bush insists he won’t make a decision before the end of this year, after the November election.

Al Cardenas, a lobbyist and high-level GOP activist who’s close to both Bush and Rubio, said both have a lengthy process to go through before they make any final decision — and before the question of a Bush-Rubio contest comes up.

First, he said, they’ll have to decide whether to take the steps necessary to gauge support, then make those calls and contacts, and then talk to major donors.

“Once they’ve done all those three things, then it’s appropropriate for them to have a conversation,” he said. “You don’t have the conversation until you have all the facts in hand.”

The deadline for all that to happen, according to Ballard, might not be until the Florida primary, likely to be in early March 2016.

Bush, with a stronger national fundraising network and better-known name, “has more luxury to wait than Rubio does,” he said.